Alimohammadi Mohammad, Dubois Noémie, Sköldberg Filip, Hallgren Asa, Tardivel Isabelle, Hedstrand Håkan, Haavik Jan, Husebye Eystein S, Gustafsson Jan, Rorsman Fredrik, Meloni Antonella, Janson Christer, Vialettes Bernard, Kajosaari Merja, Egner William, Sargur Ravishankar, Pontén Fredrik, Amoura Zahir, Grimfeld Alain, De Luca Filippo, Betterle Corrado, Perheentupa Jaakko, Kämpe Olle, Carel Jean-Claude
Department of Medical Sciences, University Hospital, Uppsala University, 751 85 Uppsala, Sweden.
Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4396-401. doi: 10.1073/pnas.0809986106. Epub 2009 Feb 26.
Patients with autoimmune polyendocrine syndrome type 1 (APS-1) suffer from multiple organ-specific autoimmunity with autoantibodies against target tissue-specific autoantigens. Endocrine and nonendocrine organs such as skin, hair follicles, and liver are targeted by the immune system. Despite sporadic observations of pulmonary symptoms among APS-1 patients, an autoimmune mechanism for pulmonary involvement has not been elucidated. We report here on a subset of APS-1 patients with respiratory symptoms. Eight patients with pulmonary involvement were identified. Severe airway obstruction was found in 4 patients, leading to death in 2. Immunoscreening of a cDNA library using serum samples from a patient with APS-1 and obstructive respiratory symptoms identified a putative potassium channel regulator (KCNRG) as a pulmonary autoantigen. Reactivity to recombinant KCNRG was assessed in 110 APS-1 patients by using immunoprecipitation. Autoantibodies to KCNRG were present in 7 of the 8 patients with respiratory symptoms, but in only 1 of 102 APS-1 patients without respiratory symptoms. Expression of KCNRG messenger RNA and protein was found to be predominantly restricted to the epithelial cells of terminal bronchioles. Autoantibodies to KCNRG, a protein mainly expressed in bronchial epithelium, are strongly associated with pulmonary involvement in APS-1. These findings may facilitate the recognition, diagnosis, characterization, and understanding of the pulmonary manifestations of APS-1.
1型自身免疫性多内分泌腺综合征（APS-1）患者患有多种器官特异性自身免疫病，体内存在针对靶组织特异性自身抗原的自身抗体。免疫系统会攻击内分泌和非内分泌器官，如皮肤、毛囊和肝脏。尽管偶有观察到APS-1患者出现肺部症状，但肺部受累的自身免疫机制尚未阐明。我们在此报告一组有呼吸道症状的APS-1患者。确定了8例有肺部受累的患者。4例患者出现严重气道阻塞，其中2例死亡。利用一名患有APS-1和阻塞性呼吸道症状患者的血清样本对cDNA文库进行免疫筛选，确定一种假定的钾通道调节蛋白（KCNRG）为肺部自身抗原。通过免疫沉淀法在110例APS-1患者中评估了对重组KCNRG的反应性。8例有呼吸道症状的患者中有7例存在抗KCNRG自身抗体，而102例无呼吸道症状的APS-1患者中只有1例存在该抗体。发现KCNRG信使核糖核酸和蛋白的表达主要局限于终末细支气管的上皮细胞。抗KCNRG自身抗体主要在支气管上皮中表达，与APS-1患者的肺部受累密切相关。这些发现可能有助于认识、诊断、描述和理解APS-1的肺部表现。
